Massive retinal gliosis: a late complication of retinal detachment surgery

Purpose Massive retinal gliosis is a rare, benign, intraocular tumor. It develops mostly in long-standing ocular disease such as chronic inflammation, vascular disorders, glaucoma, trauma, or congenital abnormalities. We report on a case of massive retinal gliosis, which developed 17 years following retinal detachment surgery.Methods Case report.Results A 64-year-old woman developed a peripheral fundus tumor 17 years after successful retinal detachment surgery. Follow-up examination demonstrated growth of the mass. The tumor was treated by pars plana vitrectomy and local endoresection. Histopathological study revealed massive reactive gliosis of the retina.Conclusions To our knowledge, this is the first histopathologically proven case of a massive retinal gliosis, which developed after a non-drainage retinal detachment surgery. Endoresection is a therapeutic option in suspected massive retinal gliosis. It provides material for histological diagnosis which obviates unnecessary intervention in a functioning eye.     

A phase II study of bendamustine chemotherapy as second-line treatment in metastatic uveal melanoma

Uveal melanoma is the most frequent primary malignant neoplasm of the eye and has a poor prognosis in metastatic stage. Fotemustine or a combination of gemcitabine and treosulfan has demonstrated some efficacy in metastatic disease. We conducted a phase II trial to assess the second-line activity and toxicity of bendamustine hydrochloride, a nucleoside analogue with alkylating activity. Inclusion criteria were a Karnofsky performance status of > or = 60% and progressive disease during or after first-line chemotherapy. Bendamustine was administered at a dose of 120 mg/m2 on days 1 and 2. Cycles were repeated on day 22. The primary endpoint of the study was the determination of the number of patients achieving an objective response or stable disease. The secondary endpoint was toxicity. Eleven patients were enrolled into the trial. Grade III and IV toxicity consisted of anaemia, thrombocytopenia and leucocytopenia in two, one and two patients, respectively. No grade III or IV non-haematological toxicity was observed. According to Response Evaluation Criteria in Solid Tumours (RECIST), all patients showed progressive disease. We conclude that bendamustine is ineffective as second-line chemotherapy for metastatic uveal melanoma.     

B-cell chronic lymphocytic leukemia with aberrant CD8 expression: genetic and immunophenotypic analysis of prognostic factors

B-cell chronic lymphocytic leukemia (B-CLL) is phenotypically characterized by cell surface co-expression of CD19, CD20, CD5, and CD23. However, the concomitant presence of other antigens distinctive of a particular leukocyte subset, e.g. T cells, is an unusual finding in B-CLL. In the present report, a case of B-CLL with aberrant expression of the T-cell-associated antigen CD8 is described. Flow cytometric analysis of the patient's cells demonstrated lack of CD38 expression, and cytogenetic analysis by FISH did not show any abnormalities of chromosomes 17p, 11q, and 12. Furthermore, the B-CLL cells expressed only low levels of the tyrosine kinase ZAP-70, which was in agreement with the mutated status of the immunoglobulin heavy-chain variable-region gene (IgVH). In summary, the determined profile of prognostic markers together with the highly stable and indolent disease in the described patient suggest a good prognosis of B-CLL with aberrant CD8 expression.     

Differentiation of neurospheres from the enteric nervous system

The enteric nervous system (ENS) derives from neural crest cells, which migrate from the neural tube into the developing gut. The neuronal and glial precursor cells migrate mainly from the oral towards the anal end of the gastrointestinal tract. So far, knowledge about the multipotent influences upon the ENS development, especially its neurotrophic support, derives mainly from knock-out models. The in vitro technique of isolating enteric neuronal precursor cells allows to study the effects of various factors upon their appropriate development in more detail. We therefore adapted the method of growing neurospheres, which are agglomerates of neuronal precursor cells and differentiated neurones and glial cells, from the central nervous system (CNS) for the ENS. The gut of NMRI mice at E12 were dissected, mildly dissociated and plated in 25-cm² culture flasks. The cultures were maintained in N1 supplemented DMEM/F12 medium with the appropriate neurotrophin cocktails (bFGF, GDNF, Neurturin, CNTF). After several days in culture most of the cells die, while the surviving cells form clusters from which domes, and later spheres arise. The spheres could be harvested and processed for further experiments. First investigations revealed, that the amount of precursor cells was much less in enteric neurospheres as seen in corresponding cultures from the CNS. We found about 43% HNK-1-NCAM+ in enteric and approximately 90% Nestin-+ cells in midbrain neurospheres. Differentiation studies of the enteric neurospheres showed that especially ciliary neurotrophic factor (CNTF) increased the number of enteric neurones (PGP positive), while the amount of HNK-1 precursor cells decreased under the influence of all tested neurotrophins but GDNF. The culture of the freshly dissociated enteric neurospheres in a three-dimensional matrix yielded a secondary network which allows to investigate the pattern formation of the ENS. The generation of enteric neurospheres and the following differentiation and 3D culture in vitro can increase our knowledge of the amount and time point of neurotrophic as well as the ECM-protein influence upon the appropriate development of the ENS.     

One-step detection of c-kit point mutations using peptide nucleic acid-mediated polymerase chain reaction clamping and hybridization probes

The prognostic significance of somatic activating codon 816 c-kit mutations in pediatric urticaria pigmentosa has not yet been established in detail. Detection of such mutations in archival paraffin-embedded biopsies is usually hampered by an abundance of surrounding normal cells. Here we describe a method for the selective amplification and specific detection of c-kit mutation Asp816-->Val in complete tissue sections cut from up to 24-year-old paraffin blocks. Peptide nucleic acid-mediated polymerase chain reaction clamping of the wild-type allele was combined with on-line mutation detection using oligonucleotide hybridization probes. In DNA extracted from HMC-1 cells heterozygously carrying the c-kit mutation Asp816-->Val, the one-tube assay allowed specific detection of this mutation in a more than 1000-fold excess of normal background DNA within 1 hour and without the need for additional analytical steps. In a series of 38 cases with pediatric urticaria pigmentosa we detected c-kit codons 815 and 816 mutations in 16 cases. Mutation detection did not correlate with clinical outcome after a mean follow-up of 11.2 years. In conclusion, the procedure described may represent an ideal screening tool for all kinds of clinical applications, using point mutations as markers of, for example, early events in carcinogenesis, circulating metastatic tumor cells, and minimal residual disease.     

Migration and differentiation of myogenic precursors following transplantation into the developing rat brain

There is increasing evidence that muscle-derived precursor cells can, under appropriate conditions, give rise to other than myogenic cell types. Transplantation into the embryonic ventricular zone provides a unique opportunity to study the migration and differentiation of non-neural somatic progenitor cells in response to instructive cues within the developing neuroepithelium. Here, we demonstrate that myogenic cell lines grafted into the ventricles of rat embryos showed widespread migration into several host brain compartments. In contrast to incorporation patterns observed after transplantation of neural cells, grafted myoblasts incorporated virtually exclusively along endogenous blood vessels. Preferential incorporation sites included cortex, olfactory bulb, hippocampus, striatum, thalamus, hypothalamus, and tectum. While the engrafted myoblasts showed no evidence of neural differentiation, a fraction exhibited pronounced coexpression of endothelial marker antigens. These findings support the concept of a close developmental relationship between the myogenic and the endothelial lineages. Used as a delivery system, transfected myoblasts may be exploited for widespread gene transfer to the perivascular compartment of the perinatal central nervous system.